Rain falling on the high, dry Chyulu Hills of Kenya filters through the lava soil until it emerges as cool, running springs at Mzima. Zebra and elephant visit the oasis to drink, but this unusual African portrait is more concerned with the animals that live at the springs. It is a fascinating world in which frogs climb trees, birds swim, turtle and crocodile feed side by side, and the lumbering hippopotamus takes on a new grace in the unique underwater photography of Alan Root.